We humans are cognitively lazy. If making a change requires thought and effort, our default is to not do anything unless there is a pressing reason to act (e.g., you just took a new job and have to choose an insurance policy).

The record highs set by large-cap stocks this year, the pullback in bond yields relative to the end of 2013, and the drop in oil prices revealed just how difficult it is to predict what the financial markets will and won’t do.